wireguard-linux/drivers/misc/ocxl/file.c, branch jd/unified-crypt-queue

ocxl: Fix concurrent AFU open and device removal

2019-12-10T09:34:23Z

If an ocxl device is unbound through sysfs at the same time its AFU is being opened by a user process, the open code may dereference freed stuctures, which can lead to kernel oops messages. You'd have to hit a tiny time window, but it's possible. It's fairly easy to test by making the time window bigger artificially. Fix it with a combination of 2 changes: - when an AFU device is found in the IDR by looking for the device minor number, we should hold a reference on the device until after the context is allocated. A reference on the AFU structure is kept when the context is allocated, so we can release the reference on the device after the context allocation. - with the fix above, there's still another even tinier window, between the time the AFU device is found in the IDR and the reference on the device is taken. We can fix this one by removing the IDR entry earlier, when the device setup is removed, instead of waiting for the 'release' device callback. With proper locking around the IDR. Fixes: 75ca758adbaf ("ocxl: Create a clear delineation between ocxl backend & frontend") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Frederic Barrat Reviewed-by: Greg Kurz Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190624144148.32022-1-fbarrat@linux.ibm.com

ocxl: Fix return value check in afu_ioctl()

2019-05-06T10:21:56Z

In case of error, the function eventfd_ctx_fdget() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). This issue was detected by using the Coccinelle software. Fixes: 060146614643 ("ocxl: move event_fd handling to frontend") Signed-off-by: Wei Yongjun Acked-by: Alastair D'Silva Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

ocxl: move event_fd handling to frontend

2019-05-02T16:55:02Z

Event_fd is only used in the driver frontend, so it does not need to exist in the backend code. Relocate it to the frontend and provide an opaque mechanism for consumers instead. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: afu_irq only deals with IRQ IDs, not offsets

2019-05-02T16:55:02Z

The use of offsets is required only in the frontend, so alter the IRQ API to only work with IRQ IDs in the backend. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: Allow external drivers to use OpenCAPI contexts

2019-05-02T16:55:02Z

Most OpenCAPI operations require a valid context, so exposing these functions to external drivers is necessary. Signed-off-by: Alastair D'Silva Reviewed-by: Greg Kurz Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: Create a clear delineation between ocxl backend & frontend

2019-05-02T16:55:01Z

The OCXL driver contains both frontend code for interacting with userspace, as well as backend code for interacting with the hardware. This patch separates the backend code from the frontend so that it can be used by other device drivers that communicate via OpenCAPI. Relocate dev, cdev & sysfs files to the frontend code to allow external drivers to maintain their own devices. Reference counting on the device in the backend is replaced with kref counting. Move file & sysfs layer initialisation from core.c (backend) to pci.c (frontend). Create an ocxl_function oriented interface for initing devices & enumerating AFUs. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman

ocxl: Rename struct link to ocxl_link

2019-05-02T16:55:00Z

The term 'link' is ambiguous (especially when the struct is used for a list), so rename it for clarity. Signed-off-by: Alastair D'Silva Reviewed-by: Greg Kurz Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()

2018-06-05T11:33:57Z

Add the missing unlock before return from function afu_ioctl_enable_p9_wait() in the error handling case. Fixes: e948e06fc63a ("ocxl: Expose the thread_id needed for wait on POWER9") Signed-off-by: Wei Yongjun Reviewed-by: Alastair D'Silva Signed-off-by: Michael Ellerman

ocxl: Add an IOCTL so userspace knows what OCXL features are available

2018-06-03T10:40:32Z

In order for a userspace AFU driver to call the POWER9 specific OCXL_IOCTL_ENABLE_P9_WAIT, it needs to verify that it can actually make that call. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman

ocxl: Expose the thread_id needed for wait on POWER9

2018-06-03T10:40:32Z

In order to successfully issue as_notify, an AFU needs to know the TID to notify, which in turn means that this information should be available in userspace so it can be communicated to the AFU. Signed-off-by: Alastair D'Silva Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman